In the manufacture of fiber reinforced resin products, sheet molding compounds are frequently used which consist of a mixture of a viscous uncured thermosetting resin and chopped fibers, such as glass fibers. In most cases the resin and chopped fibers are sandwiched between films of plastic material to form a laminated structure which is wound in coiled form. The laminate is stored under conditions which will not result in final curing of the resin. At the time of use, the laminate is uncoiled and cut to the desired size and shape for the molding position.
As the resin which is employed to provide the sheet molding compound is relatively viscous, specific procedures must be employed to provide a thorough impregnation of the resin and fibers. In the past, impregnation has been achieved by passing the laminated structure between cooperating rolls or flexing the laminate in concave and convex shapes. Even with these procedures it has been difficult to provide complete impregnation of the fibers at the edges of the laminate without squeezing the resin from the laminate. Conseqently, the fibers at the side edges of the laminate often lack proper impregnation and because of the incomplete impregnation, it is common practice to discard portions of the side edges of the laminate.